Energy Recovery System

Hadi FattahChris KorkuchScott LaceyRyan NearyColin O’Neill

Overview1. Project Scope2. Benchmarking3. Concept Choice4. Concept Description5. Detailed Design6. Manufacturing and Assembly7. Prototype Components8. Operation and Testing9. Results10. Analysis11. Cost of Prototype12. Cost Savings for Sponsor13. Conclusion

Project Scope

• ASHRAE prohibits the recirculation of air in chemistry labs

• Large amounts of energy are lost• Large amounts of money is spent on

HVAC• Any amount of energy recovered

would provide substantial savings• Our objective is to find a way to

recover energy within ASHRAE standards

Benchmarking

• Heat pipe– Heat transfer via evaporation,

condensation of fluid that moves by negative pressure, gravity and capillary action

– No contamination occurs between flows, and the system tends to be

45% - 65% effectiveness.

• Run-around coil– Indirect heat exchanger of sensible

energy between two fluid streams

– Effectiveness: 55 to 65%

Benchmarking

• Enthalpy Wheel– This system consists of a

rotary heat exchanger involving the transfer of sensible and latent heat

– Small amount of contamination may occur into inlet air stream, but fulfills ASHRAE requirements.

– 75% effectiveness (highest among its competitors).

http://www.ice-us.com/CustomSeries-Product.htm

Why Enthalpy Wheels?

• Enthalpy Wheels offer the most efficiency through the simultaneous transfer of latent and sensible energy

• Heat Pipes and Run around coils do not transfer latent heat

How an Enthalpy Wheel WorksCooling Mode (Summer)

http://labs21.lbl.gov/DPM/Assets/a3_fischer.pdf

How an Enthalpy Wheel WorksHeating Mode (Winter)

http://labs21.lbl.gov/DPM/Assets/a3_fischer.pdf

Our concept

Detailed design

Manufacturing and assembly

• 8kW of power• Temperature range

30-75 degrees @ 850 cfm

• Powered by three phase 208V, 30A rated socket

Heater

• 0-10V controller for 10 levels of heating (0=off, 10=max)• Pitot tube ensures minimum flow rate to prevent burn-up

• Steam outlet faces against airflow to maximize effectiveness.

Humidifier• 8lb/hour steam

humidification• Shares three phase

208V, 20A rated socket with fan

• Linked with control panel for automatic humidity regulation.

• Provides low cross-contamination between flows (<0.04%)

• Coated with silica gel for performance

• Rotates using small electric motor running of regular 120V socket

Enthalpy Wheel• AirXchange Inc. Model

ERC-25 Enthalpy Wheel

• Provides latent and sensible energy recovery

• Capable of 2200 cfm flow rate

• Controlled by 0 to 60Hz VFD

• Shares three phase 208V, 20A rated socket with humidifier

Fan

• 0-10V output for temperature and humidity scaled for 0%-100% RH and 0 – 100 degrees temperature scale

• Linked to control panel for active readings

• Installed on inlet and exhaust of enthalpy wheel for both streams

Temperature/Humidity Sensors

• Mounted (2) sensors in 14” section of metal duct before fan

• Average flow rate between two sensors outputs to control panel

• Volume dampers in both streams also installed to even flows by reducing flow area (if needed).

Flow Rate Meter

• Powered by regular 120V socket

• Reads temperature, humidity, and flow rates

• Linked to dehumidifier for automatic humidity control

Control Panel

Operation & Testing

Results

Temperature vs. Efficiency

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25 35 45 55 65 75 85 95

Outdoor Temperature (F)

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Analysis

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Cost of prototype

• Equipment:$13032• Labor: $434• Subcontractors:$4955• Miscellaneous: $115

AstraZeneca Cost Savings

• Winter (3 months)– Boiler creates steam to heat air– Boiler runs off Natural Gas at $5.40/MMBtu– 1 month of operation saves: $111,856

• Summer (3 months)– Chiller cools water to cool air– Chiller runs off electricity at $41.40/MWh

• Estimated yearly savings: $1,125,681

Payback Period by Region

Conclusion

• Through benchmarking and research, the best concept involved use of an Enthalpy wheel

• After designing the system in collaboration with MDavis & Energy Transfer Solutions, the prototype was built

• Experimentation supports expected results of efficiency

• Cost savings are significant, and the payback period is well within industry standards at 0-2 years.

Acknowledgements

• Special thanks to John Sorantino and Joe from MDavis & Sons, Mike Haggarty and Dave from Energy Transfer Solutions – without them prototype fabrication would not be possible

• Thanks to Professor Hartman for all the help and guidance

• Finally, and most importantly, Thank You to George Sestak and AstraZeneca – for their generous support and for this opportunity.

Questions?